NASA/ADS

Abstract

We demonstrate resonant fluorescence laser spectroscopy in highly charged ions (HCI) stored in an electron beam ion trap by investigating the dipole-forbidden 1s22s22p P3/22-P1/22 transition in boronlike Ar13+ ions. Forced evaporative cooling yielded a high resolving power, resulting in an accurate wavelength determination to λ=441.25568(26)nm. By applying stronger cooling and two-photon excitation, new optical frequency standards based upon ultrastable transitions in such HCI could be realized in the future, e.g., for the search of time variations of the fine-structure constant.